Alkali Silica Reaction in Concrete Using a New Portland Cement Made from Municipal Waste Incinerator Ash

本研究得到的结果如下：(1)在含有碎瓶玻璃骨料的砂浆中，由于碱-硅反应而测量到的膨胀远大于含有耐热玻璃骨料的砂浆。(2)与瓶装玻璃粉相比，锂玻璃粉对碱硅反应的抑制效果明显。随着锂玻璃粉的加入，膨胀率大大降低，这似乎是由于玻璃粉作为火山灰的性质和从玻璃中释放的锂。(3)在高碱水泥砂浆中，掺量高达20%的粉煤灰完全抑制了ASR的膨胀。(4)除Na2Oe为2.0和2.5%的15%煅烧含燧石砂浆具有较高的膨胀率和较低的膨胀压力外，在纵向约束下产生的膨胀压力与自由膨胀成正比。富碱砂浆的这种特殊行为似乎是由于产生了富碱的ASR凝胶。(5)膨胀压力试验结果表明，即使含有高碱含量ASR凝胶的混凝土在室内膨胀试验中表现出较大的膨胀，但受约束混凝土构件中膨胀压力引起的二次应力损伤可能并不显著。(6)在0.5 N的LiOH溶液中，锂离子通过活性骨料侵入砂浆，可以在短时间内阻止砂浆的膨胀。(7)在乙烯基袋中密封时间越长，砂浆膨胀率下降越早。(8)在离水泥浆和活性骨料颗粒界面不远的大多数ASR凝胶中，碱似乎被外部溶液提供的锂离子所取代

The results obtained in this study are as follows ;(1)Measured expansions due to the alkali silica reaction in mortars containing a crushed bottle glass aggregate were far greater than in mortars made with the Pyrex glass aggregate.(2)The lithia glass powder was conspicuously effective in the suppression of the alkali silica reaction as compared with the bottle glass powder. Great reduction in expansion with the addition of the lithia glass powder appear to be derived from the nature of the glass powder as a pozzolan and the lithium released from the glass.(3)The addition of as much as 20% fly ash completely suppressed ASR expansion even in high alkali cement mortars with the crushed bottle glass aggregate.(4)The expansive pressure generated under longitudinal restraint was in proportion to free expansion except that the 15% calcined flint-containing mortars with a high Na2Oe of 2.0 and 2.5% showed high expansions, but low expansive pressures. This exceptional behavior of the alkali-rich mortars appears to be due to the production of alkali-rich ASR gels.(5)The results obtained in the expansive pressure experiment suggest that, even if concretes containing ASR gels with a high alkali content exhibit great expansions in laboratory expansion tests, damages due to secondary stresses induced by the expansive pressure in concrete members under restraint may not be significant.(6)The intrusion of lithium ions into mortar with a reactive aggregate could arrest the expansion of mortars shortly after immersion in 0.5 N LiOH solution.(7)Expansion of mortars started decreasing earlier in mortars pre-cured in sealed in vinyl sacks for longer periods.(8)The alkalis in most ASR gels not far from interfaces between the cement paste and reactive aggregate particles appear to be replaced by the lithium ions supplied from the external solution